The present invention relates to an office machine and in particular to a tension buffer in the office machine which prevents belt from loosening or tensing when a recording head accelerates or decelerates.
FIG. 1 shows a conventional apparatus for controlling a recording head in an office machine. The conventional apparatus for controlling a recording head in an office machine includes a main body 10, a driving wheel 11, a belt 12, and a driven wheel 13, wherein the driving wheel 11, belt 12, and driven wheel 13 are disposed on the main body 10. The belt 12 links the driving wheel 11 and the driven wheel 13, and the driving wheel 11 is powered by a motor 16. A recording head 14 is slidably joined on a shaft 15 and bound to the belt 12. The driving wheel 11 drives the recording head 14 to slide on the shaft 15 through the belt 12 to spray ink.
Conventionally, the driven wheel 13 is driven by the driving wheel 11 so that the belt 12 has a predetermined tension. A resilient member 131 of the driven wheel 13 is used to balance tension. As shown in FIG. 1, when the office machine operates, the recording head 14 moves along the shaft by accelerating or decelerating. With long term use and impact, the distance between the driving wheel 11 and driven wheel 13 is altered. The driven wheel 13 is fixed by a screw 132, and the screw 132 may also be damaged. Thus, the driven wheel 13 is unable to return to the original position and the belt 12 may become too slack, or too tight. The driven wheel 13 may also be fixed by a power spring with high tension, which is detrimental as the load on the motor increases, inhibiting office machine performance.